Epidemiological characteristics of human psittacosis in Guangzhou, China, January 2021 to June 2024.

Background: Psittacosis is a global and underappreciated zoonosis, with increasing reported cases in many countries. There have been several outbreaks and even deaths of psittacosis reported in China. Understanding its epidemiological characteristics and dimensions is crucial for formulating precise prevention and control strategies. This study aimed to analyze the epidemiological characteristics of human psittacosis in Guangzhou, China.

Methods: The demographic characteristics, clinical manifestations, temporal patterns, geographic distribution and potential exposures of psittacosis in Guangzhou were analyzed based on the surveillance data and epidemiological investigation conducted between January 2021 and June 2024. Seasonal and trend decomposition using LOESS was applied to decompose the number of psittacosis cases into trend, seasonal and remainder component.

Results: A total of 148 cases were reported, with a significant increase in the number of psittacosis cases over the study period. Most of cases were sporadic and detected by metagenomic next-generation sequencing (mNGS). Psittacosis was predominant males aged 40-79 years. Fever and pneumonia were the most commonly observed clinical manifestations. A seasonal trend was observed in the number of psittacosis cases with a high prevalence of cases in December and March. A total of 108 local cases (87%) occurred in rural regions. Among local cases, 67.7% reported a history of contact with birds or poultry, and 17.7% had been exposed to a related environment. The suspected source of infection differed between urban and rural areas, with parrots being the primary source in urban areas and poultry in rural areas.

Conclusion: Increasing clinicians' awareness, enhancing epidemiological surveillance, paying close attention to the epidemic in rural areas, and implementing measures against avian influenza, will be conducive to preventing and controlling psittacosis.